Diesel engine transmission gear engagement side clearance testing method

The invention discloses a diesel engine transmission gear engagement side clearance testing method, wherein squeezing deformation is performed on a preheated plastic material through rotating a gear,and the gear clearance of the tested gear is determined by means of the thickness of the squeezed plastic material. The method comprises the following steps of S1, performing preheating processing, selecting a plastic strip, and heating the plastic strip to a temperature T; S2, performing squeezing deformation, placing the preheated plastic strip to a gullet which is next to the engaging tooth, rotating the gear for one cycle for performing squeezing deformation on the plastic strip; S3, performing squeezing deformation, continuously rotating the gear for squeezing the plastic strip by an engaging gear, and keeping for a time period H; and S4, performing thickness measurement, unloading the squeezed and formed plastic strip, measuring the thickness of the squeezed part of the plastic stripby means of a testing fix